Astroparticle Physics

Evolution and Signatures of Primordial Magnetic Fields

by Salome Mtchedlidze (Ilia State University)


Magnetic fields permeate our Universe at all cosmic scales. Radio observations reveal their large-scale coherence scales of the order of kpc and their strengths of the order of microGauss on galaxy and galaxy cluster scales. Despite their ubiquity, their origin still remains a mystery. Among different magnetogenesis scenarios, one plausible scenario is the relic magnetisation of the Universe. This idea is strengthened by an intriguing possibility of having very weak magnetic fields in cosmic voids, as hinted at by observations of blazar spectra. The importance of studies of the magnetic fields generated in the early Universe, i.e., primordial magnetic fields (PMFs), lies in them providing a new observational window to the early Universe. In our work, we explore inflation-generated and causally, phase-transition PMFs which might have unlimited correlation length scales and correlation lengths limited by the Hubble length scale at the moment of generation, respectively. We use the cosmological magnetohydrodynamical (MHD) code ENZO to evolve these PMFs during large-scale structure formation. For the first time, we account for their pre-recombination dynamics and include helical models. In this talk, I will discuss the evolution of PMFs from the early Universe till the current epoch. I will present our findings which include the distinctive evolution of different seed fields retaining the information of magnetic initial conditions on the largest scales of the Universe. I will also briefly review our preliminary results on the imprints of PMFs in galaxy clusters and talk about the future prospects of our work.

Join the meeting here: Zoom link

Meeting ID: 921 1801 0804
Passcode: 68144845